LXR linux/net/nfc/hci/hcp.c

   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                        if (ptr) {
  77                                memcpy(packet->message.data, ptr,
  78                                       data_link_len - 1);
  79                                ptr += data_link_len - 1;
  80                        }
  81                } else {
  82                        memcpy(&packet->message, ptr, data_link_len);
  83                        ptr += data_link_len;
  84                }
  85
  86                /* This is the last fragment, set the cb bit */
  87                if (hci_len == 0)
  88                        packet->header |= ~NFC_HCI_FRAGMENT;
  89
  90                skb_queue_tail(&cmd->msg_frags, skb);
  91        }
  92
  93        mutex_lock(&hdev->msg_tx_mutex);
  94
  95        if (hdev->shutting_down) {
  96                err = -ESHUTDOWN;
  97                mutex_unlock(&hdev->msg_tx_mutex);
  98                goto out_skb_err;
  99        }
 100
 101        list_add_tail(&cmd->msg_l, &hdev->msg_tx_queue);
 102        mutex_unlock(&hdev->msg_tx_mutex);
 103
 104        schedule_work(&hdev->msg_tx_work);
 105
 106        return 0;
 107
 108out_skb_err:
 109        skb_queue_purge(&cmd->msg_frags);
 110        kfree(cmd);
 111
 112        return err;
 113}
 114
 115/*
 116 * Receive hcp message for pipe, with type and cmd.
 117 * skb contains optional message data only.
 118 */
 119void nfc_hci_hcp_message_rx(struct nfc_hci_dev *hdev, u8 pipe, u8 type,
 120                            u8 instruction, struct sk_buff *skb)
 121{
 122        switch (type) {
 123        case NFC_HCI_HCP_RESPONSE:
 124                nfc_hci_resp_received(hdev, instruction, skb);
 125                break;
 126        case NFC_HCI_HCP_COMMAND:
 127                nfc_hci_cmd_received(hdev, pipe, instruction, skb);
 128                break;
 129        case NFC_HCI_HCP_EVENT:
 130                nfc_hci_event_received(hdev, pipe, instruction, skb);
 131                break;
 132        default:
 133                pr_err("UNKNOWN MSG Type %d, instruction=%d\n",
 134                       type, instruction);
 135                kfree_skb(skb);
 136                break;
 137        }
 138}
 139