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 <linux/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 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) */ 87 static 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 } 99 100 static 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 */ 108 static 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 } 126 127 static struct sk_buff *h4_dequeue(struct hci_uart *hu) 128 { 129 struct h4_struct *h4 = hu->priv; 130 return skb_dequeue(&h4->txq); 131 } 132 133 static 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 }; 143 144 int __init h4_init(void) 145 { 146 return hci_uart_register_proto(&h4p); 147 } 148 149 int __exit h4_deinit(void) 150 { 151 return hci_uart_unregister_proto(&h4p); 152 } 153 154 struct 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 } 274 EXPORT_SYMBOL_GPL(h4_recv_buf); 275