/*
* Copyright (C) 2012 Intel Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see .
*/
#define pr_fmt(fmt) "hci: %s: " fmt, __func__
#include
#include
#include
#include
#include "hci.h"
/*
* Payload is the HCP message data only. Instruction will be prepended.
* Guarantees that cb will be called upon completion or timeout delay
* counted from the moment the cmd is sent to the transport.
*/
int nfc_hci_hcp_message_tx(struct nfc_hci_dev *hdev, u8 pipe,
u8 type, u8 instruction,
const u8 *payload, size_t payload_len,
data_exchange_cb_t cb, void *cb_context,
unsigned long completion_delay)
{
struct nfc_dev *ndev = hdev->ndev;
struct hci_msg *cmd;
const u8 *ptr = payload;
int hci_len, err;
bool firstfrag = true;
cmd = kzalloc(sizeof(struct hci_msg), GFP_KERNEL);
if (cmd == NULL)
return -ENOMEM;
INIT_LIST_HEAD(&cmd->msg_l);
skb_queue_head_init(&cmd->msg_frags);
cmd->wait_response = (type == NFC_HCI_HCP_COMMAND) ? true : false;
cmd->cb = cb;
cmd->cb_context = cb_context;
cmd->completion_delay = completion_delay;
hci_len = payload_len + 1;
while (hci_len > 0) {
struct sk_buff *skb;
int skb_len, data_link_len;
struct hcp_packet *packet;
if (NFC_HCI_HCP_PACKET_HEADER_LEN + hci_len <=
hdev->max_data_link_payload)
data_link_len = hci_len;
else
data_link_len = hdev->max_data_link_payload -
NFC_HCI_HCP_PACKET_HEADER_LEN;
skb_len = ndev->tx_headroom + NFC_HCI_HCP_PACKET_HEADER_LEN +
data_link_len + ndev->tx_tailroom;
hci_len -= data_link_len;
skb = alloc_skb(skb_len, GFP_KERNEL);
if (skb == NULL) {
err = -ENOMEM;
goto out_skb_err;
}
skb_reserve(skb, ndev->tx_headroom);
skb_put(skb, NFC_HCI_HCP_PACKET_HEADER_LEN + data_link_len);
/* Only the last fragment will have the cb bit set to 1 */
packet = (struct hcp_packet *)skb->data;
packet->header = pipe;
if (firstfrag) {
firstfrag = false;
packet->message.header = HCP_HEADER(type, instruction);
if (ptr) {
memcpy(packet->message.data, ptr,
data_link_len - 1);
ptr += data_link_len - 1;
}
} else {
memcpy(&packet->message, ptr, data_link_len);
ptr += data_link_len;
}
/* This is the last fragment, set the cb bit */
if (hci_len == 0)
packet->header |= ~NFC_HCI_FRAGMENT;
skb_queue_tail(&cmd->msg_frags, skb);
}
mutex_lock(&hdev->msg_tx_mutex);
if (hdev->shutting_down) {
err = -ESHUTDOWN;
mutex_unlock(&hdev->msg_tx_mutex);
goto out_skb_err;
}
list_add_tail(&cmd->msg_l, &hdev->msg_tx_queue);
mutex_unlock(&hdev->msg_tx_mutex);
schedule_work(&hdev->msg_tx_work);
return 0;
out_skb_err:
skb_queue_purge(&cmd->msg_frags);
kfree(cmd);
return err;
}
/*
* Receive hcp message for pipe, with type and cmd.
* skb contains optional message data only.
*/
void nfc_hci_hcp_message_rx(struct nfc_hci_dev *hdev, u8 pipe, u8 type,
u8 instruction, struct sk_buff *skb)
{
switch (type) {
case NFC_HCI_HCP_RESPONSE:
nfc_hci_resp_received(hdev, instruction, skb);
break;
case NFC_HCI_HCP_COMMAND:
nfc_hci_cmd_received(hdev, pipe, instruction, skb);
break;
case NFC_HCI_HCP_EVENT:
nfc_hci_event_received(hdev, pipe, instruction, skb);
break;
default:
pr_err("UNKNOWN MSG Type %d, instruction=%d\n",
type, instruction);
kfree_skb(skb);
break;
}
}
ion>
Julian Anastasov says:
====================
net: dst_confirm replacement
This patchset addresses the problem of neighbour
confirmation where received replies from one nexthop
can cause confirmation of different nexthop when using
the same dst. Thanks to YueHaibing <yuehaibing@huawei.com>
for tracking the dst->pending_confirm problem.
Sockets can obtain cached output route. Such
routes can be to known nexthop (rt_gateway=IP) or to be
used simultaneously for different nexthop IPs by different
subnet prefixes (nh->nh_scope = RT_SCOPE_HOST, rt_gateway=0).
At first look, there are more problems:
- dst_confirm() sets flag on dst and not on dst->path,
as result, indication is lost when XFRM is used
- DNAT can change the nexthop, so the really used nexthop is
not confirmed
So, the following solution is to avoid using
dst->pending_confirm.
The current dst_confirm() usage is as follows:
Protocols confirming dst on received packets:
- TCP (1 dst per socket)
- SCTP (1 dst per transport)
- CXGB*
Protocols supporting sendmsg with MSG_CONFIRM [ | MSG_PROBE ] to
confirm neighbour:
- UDP IPv4/IPv6
- ICMPv4 PING
- RAW IPv4/IPv6
- L2TP/IPv6
MSG_CONFIRM for other purposes (fix not needed):
- CAN
Sending without locking the socket:
- UDP (when no cork)
- RAW (when hdrincl=1)
Redirects from old to new GW:
- rt6_do_redirect
The patchset includes the following changes:
1. sock: add sk_dst_pending_confirm flag
- used only by TCP with patch 4 to remember the received
indication in sk->sk_dst_pending_confirm
2. net: add dst_pending_confirm flag to skbuff
- skb->dst_pending_confirm will be used by all protocols
in following patches, via skb_{set,get}_dst_pending_confirm
3. sctp: add dst_pending_confirm flag
- SCTP uses per-transport dsts and can not use
sk->sk_dst_pending_confirm like TCP
4. tcp: replace dst_confirm with sk_dst_confirm
5. net: add confirm_neigh method to dst_ops
- IPv4 and IPv6 provision for slow neigh lookups for MSG_PROBE users.
I decided to use neigh lookup only for this case because on
MSG_PROBE the skb may pass MTU checks but it does not reach
the neigh confirmation code. This patch will be used from patch 6.
- xfrm_confirm_neigh: we use the last tunnel address, if present.
When there are only transports, the original dest address is used.
6. net: use dst_confirm_neigh for UDP, RAW, ICMP, L2TP
- dst_confirm conversion for UDP, RAW, ICMP and L2TP/IPv6
- these protocols use MSG_CONFIRM propagated by ip*_append_data
to skb->dst_pending_confirm. sk->sk_dst_pending_confirm is not
used because some sending paths do not lock the socket. For
MSG_PROBE we use the slow lookup (dst_confirm_neigh).
- there are also 2 cases that need the slow lookup:
__ip6_rt_update_pmtu and rt6_do_redirect. I hope
&ipv6_hdr(skb)->saddr is the correct nexthop address to use here.
7. net: pending_confirm is not used anymore
- I failed to understand the CXGB* code, I see dst_confirm()
calls but I'm not sure dst_neigh_output() was called. For now
I just removed the dst->pending_confirm flag and left all
dst_confirm() calls there. Any better idea?
- Now may be old function neigh_output() should be restored
instead of dst_neigh_output?
====================
Signed-off-by: David S. Miller <davem@davemloft.net>