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_obj(*h4); 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 h4->rx_skb = h4_recv_buf(hu, h4->rx_skb, data, count, 113 h4_recv_pkts, ARRAY_SIZE(h4_recv_pkts)); 114 if (IS_ERR(h4->rx_skb)) { 115 int err = PTR_ERR(h4->rx_skb); 116 bt_dev_err(hu->hdev, "Frame reassembly failed (%d)", err); 117 h4->rx_skb = NULL; 118 return err; 119 } 120 121 return count; 122 } 123 124 static struct sk_buff *h4_dequeue(struct hci_uart *hu) 125 { 126 struct h4_struct *h4 = hu->priv; 127 return skb_dequeue(&h4->txq); 128 } 129 130 static const struct hci_uart_proto h4p = { 131 .id = HCI_UART_H4, 132 .name = "H4", 133 .open = h4_open, 134 .close = h4_close, 135 .recv = h4_recv, 136 .enqueue = h4_enqueue, 137 .dequeue = h4_dequeue, 138 .flush = h4_flush, 139 }; 140 141 int __init h4_init(void) 142 { 143 return hci_uart_register_proto(&h4p); 144 } 145 146 int __exit h4_deinit(void) 147 { 148 return hci_uart_unregister_proto(&h4p); 149 } 150 151 struct sk_buff *h4_recv_buf(struct hci_uart *hu, struct sk_buff *skb, 152 const unsigned char *buffer, int count, 153 const struct h4_recv_pkt *pkts, int pkts_count) 154 { 155 u8 alignment = hu->alignment ? hu->alignment : 1; 156 struct hci_dev *hdev = hu->hdev; 157 158 /* Check for error from previous call */ 159 if (IS_ERR(skb)) 160 skb = NULL; 161 162 while (count) { 163 int i, len; 164 165 /* remove padding bytes from buffer */ 166 for (; hu->padding && count > 0; hu->padding--) { 167 count--; 168 buffer++; 169 } 170 if (!count) 171 break; 172 173 if (!skb) { 174 for (i = 0; i < pkts_count; i++) { 175 if (buffer[0] != (&pkts[i])->type) 176 continue; 177 178 skb = bt_skb_alloc((&pkts[i])->maxlen, 179 GFP_ATOMIC); 180 if (!skb) 181 return ERR_PTR(-ENOMEM); 182 183 hci_skb_pkt_type(skb) = (&pkts[i])->type; 184 hci_skb_expect(skb) = (&pkts[i])->hlen; 185 break; 186 } 187 188 /* Check for invalid packet type */ 189 if (!skb) 190 return ERR_PTR(-EILSEQ); 191 192 count -= 1; 193 buffer += 1; 194 } 195 196 len = min_t(uint, hci_skb_expect(skb) - skb->len, count); 197 skb_put_data(skb, buffer, len); 198 199 count -= len; 200 buffer += len; 201 202 /* Check for partial packet */ 203 if (skb->len < hci_skb_expect(skb)) 204 continue; 205 206 for (i = 0; i < pkts_count; i++) { 207 if (hci_skb_pkt_type(skb) == (&pkts[i])->type) 208 break; 209 } 210 211 if (i >= pkts_count) { 212 kfree_skb(skb); 213 return ERR_PTR(-EILSEQ); 214 } 215 216 if (skb->len == (&pkts[i])->hlen) { 217 u16 dlen; 218 219 switch ((&pkts[i])->lsize) { 220 case 0: 221 /* No variable data length */ 222 dlen = 0; 223 break; 224 case 1: 225 /* Single octet variable length */ 226 dlen = skb->data[(&pkts[i])->loff]; 227 hci_skb_expect(skb) += dlen; 228 229 if (skb_tailroom(skb) < dlen) { 230 kfree_skb(skb); 231 return ERR_PTR(-EMSGSIZE); 232 } 233 break; 234 case 2: 235 /* Double octet variable length */ 236 dlen = get_unaligned_le16(skb->data + 237 (&pkts[i])->loff); 238 hci_skb_expect(skb) += dlen; 239 240 if (skb_tailroom(skb) < dlen) { 241 kfree_skb(skb); 242 return ERR_PTR(-EMSGSIZE); 243 } 244 break; 245 default: 246 /* Unsupported variable length */ 247 kfree_skb(skb); 248 return ERR_PTR(-EILSEQ); 249 } 250 251 if (!dlen) { 252 hu->padding = (skb->len + 1) % alignment; 253 hu->padding = (alignment - hu->padding) % alignment; 254 255 /* No more data, complete frame */ 256 (&pkts[i])->recv(hdev, skb); 257 skb = NULL; 258 } 259 } else { 260 hu->padding = (skb->len + 1) % alignment; 261 hu->padding = (alignment - hu->padding) % alignment; 262 263 /* Complete frame */ 264 (&pkts[i])->recv(hdev, skb); 265 skb = NULL; 266 } 267 } 268 269 return skb; 270 } 271 EXPORT_SYMBOL_GPL(h4_recv_buf); 272