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 */
21 int 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
106 out_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 */
117 void 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
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