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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 *4 * Bluetooth HCI UART driver5 *6 * Copyright (C) 2000-2001 Qualcomm Incorporated7 * Copyright (C) 2002-2003 Maxim Krasnyansky <maxk@qualcomm.com>8 * Copyright (C) 2004-2005 Marcel Holtmann <marcel@holtmann.org>9 */10 11#include <linux/module.h>12 13#include <linux/kernel.h>14#include <linux/init.h>15#include <linux/types.h>16#include <linux/fcntl.h>17#include <linux/interrupt.h>18#include <linux/ptrace.h>19#include <linux/poll.h>20 21#include <linux/slab.h>22#include <linux/tty.h>23#include <linux/errno.h>24#include <linux/string.h>25#include <linux/signal.h>26#include <linux/ioctl.h>27#include <linux/skbuff.h>28#include <linux/unaligned.h>29 30#include <net/bluetooth/bluetooth.h>31#include <net/bluetooth/hci_core.h>32 33#include "hci_uart.h"34 35struct h4_struct {36 struct sk_buff *rx_skb;37 struct sk_buff_head txq;38};39 40/* Initialize protocol */41static int h4_open(struct hci_uart *hu)42{43 struct h4_struct *h4;44 45 BT_DBG("hu %p", hu);46 47 h4 = kzalloc(sizeof(*h4), GFP_KERNEL);48 if (!h4)49 return -ENOMEM;50 51 skb_queue_head_init(&h4->txq);52 53 hu->priv = h4;54 return 0;55}56 57/* Flush protocol data */58static int h4_flush(struct hci_uart *hu)59{60 struct h4_struct *h4 = hu->priv;61 62 BT_DBG("hu %p", hu);63 64 skb_queue_purge(&h4->txq);65 66 return 0;67}68 69/* Close protocol */70static int h4_close(struct hci_uart *hu)71{72 struct h4_struct *h4 = hu->priv;73 74 BT_DBG("hu %p", hu);75 76 skb_queue_purge(&h4->txq);77 78 kfree_skb(h4->rx_skb);79 80 hu->priv = NULL;81 kfree(h4);82 83 return 0;84}85 86/* Enqueue frame for transmission (padding, crc, etc) */87static int h4_enqueue(struct hci_uart *hu, struct sk_buff *skb)88{89 struct h4_struct *h4 = hu->priv;90 91 BT_DBG("hu %p skb %p", hu, skb);92 93 /* Prepend skb with frame type */94 memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);95 skb_queue_tail(&h4->txq, skb);96 97 return 0;98}99 100static const struct h4_recv_pkt h4_recv_pkts[] = {101 { H4_RECV_ACL, .recv = hci_recv_frame },102 { H4_RECV_SCO, .recv = hci_recv_frame },103 { H4_RECV_EVENT, .recv = hci_recv_frame },104 { H4_RECV_ISO, .recv = hci_recv_frame },105};106 107/* Recv data */108static int h4_recv(struct hci_uart *hu, const void *data, int count)109{110 struct h4_struct *h4 = hu->priv;111 112 if (!test_bit(HCI_UART_REGISTERED, &hu->flags))113 return -EUNATCH;114 115 h4->rx_skb = h4_recv_buf(hu->hdev, h4->rx_skb, data, count,116 h4_recv_pkts, ARRAY_SIZE(h4_recv_pkts));117 if (IS_ERR(h4->rx_skb)) {118 int err = PTR_ERR(h4->rx_skb);119 bt_dev_err(hu->hdev, "Frame reassembly failed (%d)", err);120 h4->rx_skb = NULL;121 return err;122 }123 124 return count;125}126 127static struct sk_buff *h4_dequeue(struct hci_uart *hu)128{129 struct h4_struct *h4 = hu->priv;130 return skb_dequeue(&h4->txq);131}132 133static const struct hci_uart_proto h4p = {134 .id = HCI_UART_H4,135 .name = "H4",136 .open = h4_open,137 .close = h4_close,138 .recv = h4_recv,139 .enqueue = h4_enqueue,140 .dequeue = h4_dequeue,141 .flush = h4_flush,142};143 144int __init h4_init(void)145{146 return hci_uart_register_proto(&h4p);147}148 149int __exit h4_deinit(void)150{151 return hci_uart_unregister_proto(&h4p);152}153 154struct sk_buff *h4_recv_buf(struct hci_dev *hdev, struct sk_buff *skb,155 const unsigned char *buffer, int count,156 const struct h4_recv_pkt *pkts, int pkts_count)157{158 struct hci_uart *hu = hci_get_drvdata(hdev);159 u8 alignment = hu->alignment ? hu->alignment : 1;160 161 /* Check for error from previous call */162 if (IS_ERR(skb))163 skb = NULL;164 165 while (count) {166 int i, len;167 168 /* remove padding bytes from buffer */169 for (; hu->padding && count > 0; hu->padding--) {170 count--;171 buffer++;172 }173 if (!count)174 break;175 176 if (!skb) {177 for (i = 0; i < pkts_count; i++) {178 if (buffer[0] != (&pkts[i])->type)179 continue;180 181 skb = bt_skb_alloc((&pkts[i])->maxlen,182 GFP_ATOMIC);183 if (!skb)184 return ERR_PTR(-ENOMEM);185 186 hci_skb_pkt_type(skb) = (&pkts[i])->type;187 hci_skb_expect(skb) = (&pkts[i])->hlen;188 break;189 }190 191 /* Check for invalid packet type */192 if (!skb)193 return ERR_PTR(-EILSEQ);194 195 count -= 1;196 buffer += 1;197 }198 199 len = min_t(uint, hci_skb_expect(skb) - skb->len, count);200 skb_put_data(skb, buffer, len);201 202 count -= len;203 buffer += len;204 205 /* Check for partial packet */206 if (skb->len < hci_skb_expect(skb))207 continue;208 209 for (i = 0; i < pkts_count; i++) {210 if (hci_skb_pkt_type(skb) == (&pkts[i])->type)211 break;212 }213 214 if (i >= pkts_count) {215 kfree_skb(skb);216 return ERR_PTR(-EILSEQ);217 }218 219 if (skb->len == (&pkts[i])->hlen) {220 u16 dlen;221 222 switch ((&pkts[i])->lsize) {223 case 0:224 /* No variable data length */225 dlen = 0;226 break;227 case 1:228 /* Single octet variable length */229 dlen = skb->data[(&pkts[i])->loff];230 hci_skb_expect(skb) += dlen;231 232 if (skb_tailroom(skb) < dlen) {233 kfree_skb(skb);234 return ERR_PTR(-EMSGSIZE);235 }236 break;237 case 2:238 /* Double octet variable length */239 dlen = get_unaligned_le16(skb->data +240 (&pkts[i])->loff);241 hci_skb_expect(skb) += dlen;242 243 if (skb_tailroom(skb) < dlen) {244 kfree_skb(skb);245 return ERR_PTR(-EMSGSIZE);246 }247 break;248 default:249 /* Unsupported variable length */250 kfree_skb(skb);251 return ERR_PTR(-EILSEQ);252 }253 254 if (!dlen) {255 hu->padding = (skb->len + 1) % alignment;256 hu->padding = (alignment - hu->padding) % alignment;257 258 /* No more data, complete frame */259 (&pkts[i])->recv(hdev, skb);260 skb = NULL;261 }262 } else {263 hu->padding = (skb->len + 1) % alignment;264 hu->padding = (alignment - hu->padding) % alignment;265 266 /* Complete frame */267 (&pkts[i])->recv(hdev, skb);268 skb = NULL;269 }270 }271 272 return skb;273}274EXPORT_SYMBOL_GPL(h4_recv_buf);275