cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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hcp.c (3418B)

      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}