1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * 4 * Bluetooth HCI UART driver 5 * 6 * Copyright (C) 2000-2001 Qualcomm Incorporated 7 * 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 <asm/unaligned.h> 29 30 #include <net/bluetooth/bluetooth.h> 31 #include <net/bluetooth/hci_core.h> 32 33 #include "hci_uart.h" 34 35 struct h4_struct { 36 struct sk_buff *rx_skb; 37 struct sk_buff_head txq; 38 }; 39 40 /* Initialize protocol */ 41 static 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 */ 58 static 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 */ 70 static int h4_close(struct hci_uart *hu) 71 { 72 struct h4_struct *h4 = hu->priv; 73 74 hu->priv = NULL; 75 76 BT_DBG("hu %p", hu); 77 78 skb_queue_purge(&h4->txq); 79 80 kfree_skb(h4->rx_skb); 81 82 hu->priv = NULL; 83 kfree(h4); 84 85 return 0; 86 } 87 88 /* Enqueue frame for transmittion (padding, crc, etc) */ 89 static int h4_enqueue(struct hci_uart *hu, struct sk_buff *skb) 90 { 91 struct h4_struct *h4 = hu->priv; 92 93 BT_DBG("hu %p skb %p", hu, skb); 94 95 /* Prepend skb with frame type */ 96 memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1); 97 skb_queue_tail(&h4->txq, skb); 98 99 return 0; 100 } 101 102 static const struct h4_recv_pkt h4_recv_pkts[] = { 103 { H4_RECV_ACL, .recv = hci_recv_frame }, 104 { H4_RECV_SCO, .recv = hci_recv_frame }, 105 { H4_RECV_EVENT, .recv = hci_recv_frame }, 106 }; 107 108 /* Recv data */ 109 static int h4_recv(struct hci_uart *hu, const void *data, int count) 110 { 111 struct h4_struct *h4 = hu->priv; 112 113 if (!test_bit(HCI_UART_REGISTERED, &hu->flags)) 114 return -EUNATCH; 115 116 h4->rx_skb = h4_recv_buf(hu->hdev, h4->rx_skb, data, count, 117 h4_recv_pkts, ARRAY_SIZE(h4_recv_pkts)); 118 if (IS_ERR(h4->rx_skb)) { 119 int err = PTR_ERR(h4->rx_skb); 120 bt_dev_err(hu->hdev, "Frame reassembly failed (%d)", err); 121 h4->rx_skb = NULL; 122 return err; 123 } 124 125 return count; 126 } 127 128 static struct sk_buff *h4_dequeue(struct hci_uart *hu) 129 { 130 struct h4_struct *h4 = hu->priv; 131 return skb_dequeue(&h4->txq); 132 } 133 134 static const struct hci_uart_proto h4p = { 135 .id = HCI_UART_H4, 136 .name = "H4", 137 .open = h4_open, 138 .close = h4_close, 139 .recv = h4_recv, 140 .enqueue = h4_enqueue, 141 .dequeue = h4_dequeue, 142 .flush = h4_flush, 143 }; 144 145 int __init h4_init(void) 146 { 147 return hci_uart_register_proto(&h4p); 148 } 149 150 int __exit h4_deinit(void) 151 { 152 return hci_uart_unregister_proto(&h4p); 153 } 154 155 struct sk_buff *h4_recv_buf(struct hci_dev *hdev, struct sk_buff *skb, 156 const unsigned char *buffer, int count, 157 const struct h4_recv_pkt *pkts, int pkts_count) 158 { 159 struct hci_uart *hu = hci_get_drvdata(hdev); 160 u8 alignment = hu->alignment ? hu->alignment : 1; 161 162 /* Check for error from previous call */ 163 if (IS_ERR(skb)) 164 skb = NULL; 165 166 while (count) { 167 int i, len; 168 169 /* remove padding bytes from buffer */ 170 for (; hu->padding && count > 0; hu->padding--) { 171 count--; 172 buffer++; 173 } 174 if (!count) 175 break; 176 177 if (!skb) { 178 for (i = 0; i < pkts_count; i++) { 179 if (buffer[0] != (&pkts[i])->type) 180 continue; 181 182 skb = bt_skb_alloc((&pkts[i])->maxlen, 183 GFP_ATOMIC); 184 if (!skb) 185 return ERR_PTR(-ENOMEM); 186 187 hci_skb_pkt_type(skb) = (&pkts[i])->type; 188 hci_skb_expect(skb) = (&pkts[i])->hlen; 189 break; 190 } 191 192 /* Check for invalid packet type */ 193 if (!skb) 194 return ERR_PTR(-EILSEQ); 195 196 count -= 1; 197 buffer += 1; 198 } 199 200 len = min_t(uint, hci_skb_expect(skb) - skb->len, count); 201 skb_put_data(skb, buffer, len); 202 203 count -= len; 204 buffer += len; 205 206 /* Check for partial packet */ 207 if (skb->len < hci_skb_expect(skb)) 208 continue; 209 210 for (i = 0; i < pkts_count; i++) { 211 if (hci_skb_pkt_type(skb) == (&pkts[i])->type) 212 break; 213 } 214 215 if (i >= pkts_count) { 216 kfree_skb(skb); 217 return ERR_PTR(-EILSEQ); 218 } 219 220 if (skb->len == (&pkts[i])->hlen) { 221 u16 dlen; 222 223 switch ((&pkts[i])->lsize) { 224 case 0: 225 /* No variable data length */ 226 dlen = 0; 227 break; 228 case 1: 229 /* Single octet variable length */ 230 dlen = skb->data[(&pkts[i])->loff]; 231 hci_skb_expect(skb) += dlen; 232 233 if (skb_tailroom(skb) < dlen) { 234 kfree_skb(skb); 235 return ERR_PTR(-EMSGSIZE); 236 } 237 break; 238 case 2: 239 /* Double octet variable length */ 240 dlen = get_unaligned_le16(skb->data + 241 (&pkts[i])->loff); 242 hci_skb_expect(skb) += dlen; 243 244 if (skb_tailroom(skb) < dlen) { 245 kfree_skb(skb); 246 return ERR_PTR(-EMSGSIZE); 247 } 248 break; 249 default: 250 /* Unsupported variable length */ 251 kfree_skb(skb); 252 return ERR_PTR(-EILSEQ); 253 } 254 255 if (!dlen) { 256 hu->padding = (skb->len - 1) % alignment; 257 hu->padding = (alignment - hu->padding) % alignment; 258 259 /* No more data, complete frame */ 260 (&pkts[i])->recv(hdev, skb); 261 skb = NULL; 262 } 263 } else { 264 hu->padding = (skb->len - 1) % alignment; 265 hu->padding = (alignment - hu->padding) % alignment; 266 267 /* Complete frame */ 268 (&pkts[i])->recv(hdev, skb); 269 skb = NULL; 270 } 271 } 272 273 return skb; 274 } 275 EXPORT_SYMBOL_GPL(h4_recv_buf); 276