1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2012  Intel Corporation. All rights reserved.
4 */
5
6#define pr_fmt(fmt) "hci: %s: " fmt, __func__
7
8#include <linux/init.h>
9#include <linux/kernel.h>
10#include <linux/module.h>
11
12#include <net/nfc/hci.h>
13
14#include "hci.h"
15
16/*
17 * Payload is the HCP message data only. Instruction will be prepended.
18 * Guarantees that cb will be called upon completion or timeout delay
19 * counted from the moment the cmd is sent to the transport.
20 */
21int nfc_hci_hcp_message_tx(struct nfc_hci_dev *hdev, u8 pipe,
22			   u8 type, u8 instruction,
23			   const u8 *payload, size_t payload_len,
24			   data_exchange_cb_t cb, void *cb_context,
25			   unsigned long completion_delay)
26{
27	struct nfc_dev *ndev = hdev->ndev;
28	struct hci_msg *cmd;
29	const u8 *ptr = payload;
30	int hci_len, err;
31	bool firstfrag = true;
32
33	cmd = kzalloc(sizeof(struct hci_msg), GFP_KERNEL);
34	if (cmd == NULL)
35		return -ENOMEM;
36
37	INIT_LIST_HEAD(&cmd->msg_l);
38	skb_queue_head_init(&cmd->msg_frags);
39	cmd->wait_response = (type == NFC_HCI_HCP_COMMAND) ? true : false;
40	cmd->cb = cb;
41	cmd->cb_context = cb_context;
42	cmd->completion_delay = completion_delay;
43
44	hci_len = payload_len + 1;
45	while (hci_len > 0) {
46		struct sk_buff *skb;
47		int skb_len, data_link_len;
48		struct hcp_packet *packet;
49
50		if (NFC_HCI_HCP_PACKET_HEADER_LEN + hci_len <=
51		    hdev->max_data_link_payload)
52			data_link_len = hci_len;
53		else
54			data_link_len = hdev->max_data_link_payload -
55					NFC_HCI_HCP_PACKET_HEADER_LEN;
56
57		skb_len = ndev->tx_headroom + NFC_HCI_HCP_PACKET_HEADER_LEN +
58			  data_link_len + ndev->tx_tailroom;
59		hci_len -= data_link_len;
60
61		skb = alloc_skb(skb_len, GFP_KERNEL);
62		if (skb == NULL) {
63			err = -ENOMEM;
64			goto out_skb_err;
65		}
66		skb_reserve(skb, ndev->tx_headroom);
67
68		skb_put(skb, NFC_HCI_HCP_PACKET_HEADER_LEN + data_link_len);
69
70		/* Only the last fragment will have the cb bit set to 1 */
71		packet = (struct hcp_packet *)skb->data;
72		packet->header = pipe;
73		if (firstfrag) {
74			firstfrag = false;
75			packet->message.header = HCP_HEADER(type, instruction);
76		} else {
77			packet->message.header = *ptr++;
78		}
79		if (ptr) {
80			memcpy(packet->message.data, ptr, data_link_len - 1);
81			ptr += data_link_len - 1;
82		}
83
84		/* This is the last fragment, set the cb bit */
85		if (hci_len == 0)
86			packet->header |= ~NFC_HCI_FRAGMENT;
87
88		skb_queue_tail(&cmd->msg_frags, skb);
89	}
90
91	mutex_lock(&hdev->msg_tx_mutex);
92
93	if (hdev->shutting_down) {
94		err = -ESHUTDOWN;
95		mutex_unlock(&hdev->msg_tx_mutex);
96		goto out_skb_err;
97	}
98
99	list_add_tail(&cmd->msg_l, &hdev->msg_tx_queue);
100	mutex_unlock(&hdev->msg_tx_mutex);
101
102	schedule_work(&hdev->msg_tx_work);
103
104	return 0;
105
106out_skb_err:
107	skb_queue_purge(&cmd->msg_frags);
108	kfree(cmd);
109
110	return err;
111}
112
113/*
114 * Receive hcp message for pipe, with type and cmd.
115 * skb contains optional message data only.
116 */
117void nfc_hci_hcp_message_rx(struct nfc_hci_dev *hdev, u8 pipe, u8 type,
118			    u8 instruction, struct sk_buff *skb)
119{
120	switch (type) {
121	case NFC_HCI_HCP_RESPONSE:
122		nfc_hci_resp_received(hdev, instruction, skb);
123		break;
124	case NFC_HCI_HCP_COMMAND:
125		nfc_hci_cmd_received(hdev, pipe, instruction, skb);
126		break;
127	case NFC_HCI_HCP_EVENT:
128		nfc_hci_event_received(hdev, pipe, instruction, skb);
129		break;
130	default:
131		pr_err("UNKNOWN MSG Type %d, instruction=%d\n",
132		       type, instruction);
133		kfree_skb(skb);
134		break;
135	}
136}
137